Author Topic: Won't rev unless the brakes applied  (Read 3349 times)

Auld.Nick

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Won't rev unless the brakes applied
« on: October 10, 2014, 09:43:30 PM »
Can anyone explain to me the mechanism behind not being able to start without the brake lever being applied?

I have no problem staring my Agility.  The problem is that it won't rev unless I have one or other of the break levers squeezed. 

I'm trying to figure out what is going on and how to fix it.

I can't ride (or get my scooter to the mechanic) as it won't rev without the brake applied, with the brakes applied it won't move.

Thanks

MaryK

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Re: Won't rev unless the brakes applied
« Reply #1 on: October 10, 2014, 10:32:37 PM »
I have no answer, but a bit more information might help with a solution.
What does happen when you try to rev the engine without the brakes being applied  ?

Engine RPMs stay the same ?
Engine dies ?

good luck,

New Rider in 2010

2009 GrandVista 250

BettinANDlosing

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Re: Won't rev unless the brakes applied
« Reply #2 on: October 11, 2014, 01:52:59 AM »
CHECK YOUR MAIN GROUND!!!!!!! the lump connects to the frame near the back of the scoot, had the EXACT same thing with a customers bike, took ages to track it down and just ended up being a loose ground!!!!
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

zombie

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Re: Won't rev unless the brakes applied
« Reply #3 on: October 11, 2014, 02:40:45 AM »
Nice one B&L. When the brakes are applied it is enough resistance thru the bulbs to "act as a ground.

Nice!

I would have suggested taking the air out of the tires, and installing Helium. (just for a giggle)
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

BettinANDlosing

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Re: Won't rev unless the brakes applied
« Reply #4 on: October 11, 2014, 03:46:55 AM »
The bike i was working on was so weird, i thought it was the CDI acting up, replaced it, drove about ten miles totally fine sent it back out to the customer. A few days later he said the same thing was starting to happen. Every time swapping a new cdi would remedy it shortly lol. It was a people 150.
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

Auld.Nick

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Re: Won't rev unless the brakes applied
« Reply #5 on: October 11, 2014, 07:04:18 PM »
******************************************************
I have no answer, but a bit more information might help with a solution.
What does happen when you try to rev the engine without the brakes being applied  ?

Engine RPMs stay the same ?
Engine dies ?
*******************************************************

When I rev the engine without the brakes applied there is no increase in revs.  There is a slight change in engine noise but it is minor. 

When I reved the engine with the brakes applied for several minutes yesterday the engine eventually died.  I was subsequently unable to re-start.  I went back out after a few minutes (perhaps 5) and it stared fine.

As soon as it stops raining I check the main ground as suggested by B&L.

Thanks to all

zombie

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Re: Won't rev unless the brakes applied
« Reply #6 on: October 11, 2014, 11:35:56 PM »
Don't post, and run... We need people to convert into soldiers to fight the Free Masons when they decide to stop drinking, and attack.

One of them told us they started Ebola!
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

blue

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Re: Won't rev unless the brakes applied
« Reply #7 on: October 13, 2014, 02:16:18 AM »
Sounds like a bad switch.sometimes the brack switch will not work right if the spring on it is broke.

Auld.Nick

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Re: Won't rev unless the brakes applied
« Reply #8 on: October 14, 2014, 07:55:53 PM »
Looks like BettinANDlosing was right it's a ground problem.  Basically if I turn the blinkers on or the have the front light on 'passing' it revs.  With the blinkers on it revs in tune with when the light is on.

Now I just have to figure out how to fit it.


zombie

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Re: Won't rev unless the brakes applied
« Reply #9 on: October 14, 2014, 10:49:25 PM »
Run an 8 or 10 awg wire from the engine to the frame.

Better yet find the loose one, and repair it.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

BettinANDlosing

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Re: Won't rev unless the brakes applied
« Reply #10 on: October 15, 2014, 02:10:51 AM »
Yeah just as a test take jumper cables from the battery to the frame and see if that helps. On the people 150 and my b&w the main ground is under the right side panel on the frame.
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

zombie

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Re: Won't rev unless the brakes applied
« Reply #11 on: October 15, 2014, 02:41:53 AM »
quote: B&L.
"Yeah just as a test take jumper cables from the battery to the frame "

zzzzzto the engine. The bikes extras are working... the engine isn't.  We know that's what you meant!
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

BettinANDlosing

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Re: Won't rev unless the brakes applied
« Reply #12 on: October 15, 2014, 03:32:32 AM »
Durrrr nice catch haha
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

Auld.Nick

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Re: Won't rev unless the brakes applied
« Reply #13 on: October 20, 2014, 09:10:57 PM »
Over the weekend I removed some of the plastic and traced the ground cables from the -ve battery terminal to the frame and the engine.  I check the continuity of both wires and the continuity from the battery to the engine and from the battery to the frame.  All were fine.

Connecting the battery to the engine or  frame using jump cables did not solve the problem.  I checked the continuity of my cables and they were also fine.

Before I give up and duct tape of the headlight switch (keeping it in passing mode) is there another ground wire, fuse I should check?   

Thanks

zombie

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Re: Won't rev unless the brakes applied
« Reply #14 on: October 20, 2014, 11:25:28 PM »
Two other maybe's... It could be 1/2 of the AC output to the cdi is missing. Set a meter across the stator outputs. It should be around 240v AC at 2k rpm.
The other maybe is the coil ground. Disconnect the ground side, and attach a new wire to any good ground, and the coil.

Just another thought... The mass of green wire is ground on the bike. Perhaps that ground is faulty. Put a test light or meter on any ground point on the bike, and check for +12 volts.
"They have nothing in their whole imperial arsenal that can break the spirit of one Irishman who doesn't want to be broken."   Bobby Sands...

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